Among all the data storage solutions, the optical disks are becoming more and more important for backing up data and exchanging information because the optical storage disks have many advantages including a high storage capacity, easy to handle, and a long preserving time for the stored data. The optical disk drive also becomes more popular for this reason, and there are many types of the optical disk drive being provided for different users such as H/H type, slim type, slot-in type, and so on. Till now, the optical disk drive of slot-in type can be found all around such as notebook or laptop computers, DVD players, and even some instruments or electronic products with built-in microprocessors.
A conventional disk drive of slot-in type generally includes a casing having a front wall formed with a disk entrance-and-exit slot, and a disk transport mechanism disposed in the casing adjacent to the entrance-and-exit slot. Referring to FIGS. 1 to 4, the disk transport mechanism 8 generally includes a transport roller (not shown) disposed movably in the casing (not visible), a stationary chassis 1 disposed within the casing and aligned with the entrance-and-exit slot (not visible), a pair of front disk-guiding members (not visible) disposed adjacent to the entrance-and-exit slot, a pair of rear disk-guiding members disposed distal from the entrance-and-exit slot, a pair of disk-positioning members 81, 82 mounted on two opposite sides of the chassis 1 and disposed between the front and rear disk-guiding members, as shown in FIG. 5.
Upon detecting presence of an optical disk near the entrance-and-exit slot in the casing, the transport roller is actuated to rotate in a first direction in such a manner to draw the optical disk inward via the entrance-and-exit slot against biasing action of the front and rear disk-guiding members. The periphery of the optical disk will abut and push the front and rear disk-guiding members and to a temporary position within the casing. The disk 9 is retained temporarily at the temporary position (see FIG. 4) and is later conveyed to a reading and/or writing position, where the disk 9 is disposed securely onto a rotating seat 2 with the assistance of a clamp 4 (see FIG. 6).
One disadvantage of the aforesaid conventional disk drive is that the casing is not always allowed to be kept in the horizontal position (i.e. the entrance-and-exit slot in the casing extends in a horizontal direction), but sometimes the casing is required to be kept in the vertical position (i.e. the entrance-and-exit slot in the casing extends in a vertical direction) due to some reasons, such as due to limited space in an automobile. Under this condition, when the disk 9 is retained temporarily at the temporary position, the periphery of the disk 9 contacts the lower disk-positioning member 81 by virtue of its gravity weight so that the disk 9 is not coaxial with the rotating seat (sees FIG. 4 and 5). In order to position the disk 9 to be coaxial with the rotating seat, the distance between the disk-positioning members 81, 82 is closed to the diameter of the disk 9 (sees FIG. 6). Since the disk 9 is not required to be rotated at the temporarily position, no problems arise. However, the disk-positioning members 81, 82 hinder smooth rotation of the disk 9 at the reading and/or writing position.